Cleaning & Corrosion Flashcards
Which of the following is an acceptable first step procedure to help prevent scratching when cleaning a transparent plastic surface?
Flush the surface with clean water
When an anodized surface coating is damaged in serviced, it can be partially restored by
Chemical surface treatment
What should be done to prevent rapid deterioration when oil or grease come in contact with a tire?
Wipe the tire with a dry cloth followed by a wash down and rinse with soap and water.
Which of the following are acceptable to use in cleaning anodized surfaces?
1) steel wool
2) Brass wire brush
3) Aluminum wool
4) Stainless steel wire brush
5) fiber bristle brush
3&5
One way of obtaining increased resistance to stress corrosion cracking is by
Creating compressive stresses (via shot peening) on the metal surface
Which of the following may not be detectable even by careful visual inspection of the surface of aluminum alloy parts or structures?
Intergranular corrosion
Which of the following are acceptable to use when utilizing chemical cleaning agents on aircraft?
1) Synthetic fiber wiping cloths when using a flammable agent.
2) Cotton giber wiping cloths when using a flammable agent.
3) Atomizing spray equipment.
2 and 3
A primary reason why ordinary or otherwise non approved cleaning compounds should not be used when washing aircraft is because their use can result in
Hydrogen embrittlement in metal structures
Nickel-cadmium battery cases and drain surfaces which have been affected by electrolyte should be neutralized with a solution of
Boric acid
Which of these materials is the most anodic
Magnesium
Why is it important not to rotate the crankshaft after the corrosion preventive mixture has been put into the cylinders on engines prepared for storage?
The seal of corrosion preventive mixture will be broken
Which of the following are desired effects of using alodine on aluminum alloy?
1) A slightly rough surface
2) Relieved surface stresses
3) A smooth painting surface
4) Increased corrosion resistance
1 and 4
Select the solvent used to clean acrylics and rubber
Aliphatic naptha
A primary cause of intergranular corrosion is
Improper heat treatment
Spilled mercury on aluminum
Cause rapid and server corrosion that is very difficult to control
Select the solvent recommended for wipe down of cleaned surfaces just before painting
Aliphatic naptha
Which of the listed conditions is NOT one of the requirements for corrosion to occur?
The presence of a passive oxide film.
The lifting or flaking of the metal at the surface due to delamination of grain boundaries caused by the pressure of corrosion residual product buildup is called
Exfoliation
Corrosion caused by galvanic action is the result of
Contact between two unlike metals
For which of the following reasons would a water break test be conducted?
To make certain that bare metal surface is thoroughly clean
Corrosion should be removed from magnesium parts with a
Stiff, nonmetallic brush
Fretting corrosion is most likely to occur
When two surfaces fit tightly together but can move relative to one another.
1) In the corrosion process, it is the cathodic area of dissimilar cathodic material that corrodes.
2) In the galvanic or electro-chemical series for metals, the most anodic metals or those that will give up electrons most easily.
Regarding the above statements,
only no.2 is true.
Of the following, when and/or where is galvanic corrosion is most likely to occur?
At the interface of a steel fastener and aluminum alloy inspection plate in the presence of an electrolyte
Galvanic corrosion is likely to be most rapid and sever when
The surface area of the anodic metal is smaller than the surface area of the cathodic metal.
A nonelectrolytic chemical treatment for aluminum alloys to increase corrosion resistance and paint bonding qualities is called
Alodizing
The rust or corrosion that occurs with most metals is the result of
A tendency for them to return to their natural state.
Fayed surfaces cause concern in chemical cleaning because of the danger of
Entrapping corrosive materials.
How many magnesium engine parts be cleanes?
Wash with a commercial solvent, decarbonize, and scrape or grit blast.
Caustic cleaning products used on aluminum structures have the effect of producing
Corrosion
Intergranular corrosion in aluminum alloy parts
Cannot always be detected by surface indications.
Which of these materials is the most cathodic?
Stainless steel
What may be used to remove corrosion from highly stressed steel surfaces?
Fine grit aluminum oxide
The interior surface if sealed structural steel tubing would be best protected against corrosion by which of the following?
A coating of linseed oil.
